Just like in the single-player game, you don't create your own creatures with the engine -- the Creator software is instead used to customize and outfit some of the hundred creatures you collect with ability-modifying loot (those 100 creatures are made up of 25 base types, which are tuned per a few different variants balanced for playstyles or the game modes). But you do put your squad together from all of the characters you've found -- each player chooses three different creatures to fight with, and each of those creatures brings three abilities of their own, as well as one team ability each that all squad members can use. In the team I played with, I ran with a ranged caster and two melee fighters, but their team abilities gave me the option to blink (teleport), heal, and do some burst AoE with each one, multiplying the various strategies I could use.
You can switch out squad members at any time (though there's a short cooldown on switching), and in PvP, switching characters clears debuffs, so you can avoid getting stunned or poisoned by switching at the right time. And when you combine hitting the ability hotkeys with the pattern of switching members to counter matchups, the overall feel of the Arena mode is akin to the hardcore games that Arsers mentioned: World of Warcraft's Arena mode, and League of Legends or the old Defense of the Ancients mod.
In fact, tropes and standbys from those other games arose even in the short time that I played with Darkspore's 1v1 mode -- healing turns out to be a huge benefit while trying to survive your opponent's attacks, and so using the equivalent of the Rogue/Mage/Priest team combo in WoW works well in Darkspore, too. But as the game is being developed, said Arsers, new combos and strategies are coming up all the time. One hero that hastes everyone on the map can be combined with another that can leech haste, "so the idea is that you haste people and then you can steal the buff off of them. And all of a sudden, your whole party is hasted. I don't think we've really explored all of the combos," Arsers told me. "There's just a lot of space to play around with right now."
If that sounds like the kind of gameplay that could get e-sports fans excited, you're right. "I would love to see that develop," Arsers says. But while a pro competitive interest in the game would be nice, Arsers is more concerned right now about nailing down the feel. "The main thing for us is just to get that experience really tight, so that the people who do want it are going to find it satisfying."
It's not perfect yet. Since the gameplay is so ability-based, one issue the team is currently having is that when players run out of mana, the game immediately gets boring -- neither player can do much but chase the other around. That's fixable, though – I suggested just putting mana potions in the arena maps, and Arsers said another option they were considering was to allow switched-out team members to regenerate mana while offscreen. Currently, each match is a best-of-3, with only the loser getting to change their squad members post-fight, but that may change as well.
The devs are also trying to figure out exactly how to integrate PvP into the full-game experience. I was only shown a 1v1 arena, but Arsers said the team is really trying to balance for 2v2, and they'll likely have a number of brackets available for players to play with peers as they move through the single-player campaign. There won't be premade characters, as the team wants players to play with the characters they've built and developed in the rest of the game, but they're working to get the balance right anyway, despite competitors having different levels of loot and characters at hand.
's PvP mode is showing promise on the plan to combine the Spore
name with a more hardcore title. The game's still in heavy development (and the February 2011 planned release looks a little closer than the build I saw would suggest), but the core mechanics of an interesting PvP experience are there and working.